Using a porcupine’s quill, several small pieces of paper, a strip of polyester film, and a small metal pick that resembled a dental tool, Museum of Fine Arts conservator Pam Hatchfield carefully plucked history from a box Tuesday night.

The box was a time capsule, many of its items first placed beneath the cornerstone of the Massachusetts State House 220 years ago to mark the start of the building’s construction. The history came in many forms.

There were five neatly folded newspapers, a collection of 23 coins dating as far back as 1652, a medal depicting George Washington, a replica of Colonial records, and a silver plate commemorating the erection of the new State House.

Advertisement

“This cornerstone of a building intended for the use of the legislative and executive branches of the government of the Commonwealth of Massachusetts was laid by his Excellency Samuel Adams, Esquire, governor of the said Commonwealth,” said Michael Comeau, executive director of the Massachusetts Archives, reading from the plate’s inscription.

Paul Revere helped Adams plant the plate and other relics, he read. So did William Scollay, a colonel in the Revolutionary War.

“How cool,” Comeau said, “is that.”

The unveiling, before a bank of television cameras and a collection of dignitaries including departing Governor Deval Patrick, came just a month after Hatchfield, lying on a muddy wooden plank at the State House, spent six hours carefully chipping the time capsule from the underside of the cornerstone.

The contents were not a surprise. They had been carefully cataloged after a group of workers building an addition to the State House stumbled upon them in 1855. But the detail — the partially obscured names of the newspapers, the “quar.dol” notation on one of the coins, the wording of the silver plate’s inscription — inspired delight as Hatchfield dug deeper and deeper into the box.

Advertisement

Pam Hatchfield, a conservator at the Museum of Fine Arts, held a silver plaque that was inside the time capsule. (Jessica Rinaldi/Globe Staff)

“This is what we as conservators live for,” she said.

There was considerable ceremony surrounding the unveiling, which took place in the museum’s Art of the Americas wing, in front of Thomas Sully’s grand painting, “The Passage of the Delaware,” depicting George Washington on horseback in 1776.

But there was far more pageantry surrounding the original placement of the time capsule.

On July 4, 1795, 15 white horses — one for each state of the union — pulled the cornerstone for the new State House through the streets of Boston to the building site.

Adams arrived with an escort of fusiliers. And amid a 15-gun salute, the governor, Revere, and Scollay placed the original contents of the capsule, sandwiched between two sheets of lead. Adams dedicated the building to core principles that should “there be fixed, unimpaired, in full vigor, till time shall be no more.”

After the workers came across the time capsule in 1855, its contents were cleaned and cataloged. Officials added newspapers and coins from their own era, placed everything in a brass box, and put it in a carved depression in a new stone in the original spot.

The new capsule would remain there for 159 years, from the administration of Know-Nothing Governor Henry Gardner, through the tenure of Republican Governor Calvin Coolidge, and deep into the second term of Democrat Patrick.

But in May, water marks discovered in a section of the State House basement once used for loading coal prompted a water infiltration investigation. And officials identified the cornerstone as an area of concern.

Advertisement

At about 4:30 in the afternoon on a cold December day, after her arduous efforts to free the capsule, MFA conservator Hatchfield sat up to applause, holding a small box turned green with time.

The capsule, a little smaller than a cigar box, was taken to the museum by State Police escort. And three days later, conservationists X-rayed it in the museum’s high-tech research laboratory.

The images appeared to show the objects described in an 1855 account of the reburial. There were a few mysteries, though.

There appeared to be an extra coin in the box. What was it? And while the X-rays suggested the items were in good condition, it was difficult to know.

Would there be signs of corrosion on the coins, which were washed in nitric acid before they were reburied in 1855? And would the newspapers be in good condition?

The unveiling found the newspapers — what looked like an old copy of the Boston Bee, perhaps two copies of the old Traveller, and a couple of unknowns — in relatively good shape. Some of the coins appeared corroded. The mystery of the extra coin had not been solved as of Tuesday evening.

Secretary of State William Galvin, who is also chairman of the Massachusetts Historical Commission, second from left, pointed to an object as Governor Deval Patrick, center, looked on. (Jessica Rinaldi/Globe Staff)

All of the attention, if exciting, was a bit jarring for the conservationists overseeing the project. “We very rarely work under the klieg lights,” said Hatchfield, in an interview Tuesday afternoon, describing a profession that prizes careful, almost “glacial” restorative work.

Advertisement

There was considerable anxiety, in the run-up to the unveiling, that Hatchfield would have to halt the opening mid-lift and send everyone home disappointed. What if the newspapers were stuck to the top of the box? The sticking was minimal.

Now that the capsule has been opened, a number of questions face state officials and MFA preservationists. How much to restore coins whose condition, however poor, is an important piece of history? Should the newspapers be unfolded or left as they are? Should the state add some 21st-century items to the time capsule or not?

Secretary of State William Galvin said that’s up for debate, though he suggested he did not want to “taint” the historical feel of the capsule with new materials.

Galvin said the MFA will probably display the items from the time capsule later this year. Then, he said, he would like to stash it in the cornerstone of the State House once again.